Politicization can be described as the shading of analysis to fit prevailing policy or politics.
Politicization of Intelligence occurs when intelligence analysis is skewed, either deliberately or inadvertently, to give policymakers the results they desire.
There are generally three most well-documented ways in which finished intelligence can be corrupted:
(From James J. Drylie's Intelligence document, www.kean.edu)
Richard Betts
Robert Jervis